1. Field of the Invention
This invention relates to a meter encoding register having tapered apertures in a baffle insert.
2. Description of the Prior Art
The encoding of meter readings for use in remote reading telemetry systems is well known. In a utility meter, registers provide a readout of the total consumption of the measured quantity, such as kilowatt-hours of electrical energy in a watthour meter, by converting the sum of rotations of a meter shaft into calibrated dial readings. Watthour meter registers are typically provided with four or five dials each having an associated pointer shaft which are driven by a gear train system from the rotating meter movement. The five dials, for example, have readings in units, tens, hundreds, thousands, and ten thousands of the quantity to be measured, for example, kilowatt-hours. The register has a predetermined ratio constant which is related to the consumption of the quantity to be measured and the rate of rotation of the metering movement produced by the consumption of one unit of the quantity to be measured. In an encoding register, the angular position of each of the dial pointer shafts is converted, or encoded, into an electrical binary or digital signal. In remote utility meter reading systems, encoding at the meter permits the electrical signal representation to be compared to the register dial reading at the meter site.
In U.S. Pat. No. 4,037,219 issued July 19, 1977 to Arthur Lewis and assigned to the assignee of this invention, there is disclosed and claimed an optoelectronic meter register encoder wherein a notched pattern disk, or code wheel, is mounted to each of a plurality of pointer shafts. The code wheels actuate photosensitive pickups, or photocells, to produce a multiplebit binary code representation of the angular position of each pointer shaft. In accordance with the known construction of meter registers, the pointer shafts are interconnected by gearing so as to have a predetermined ratio such as a ratio of 1 to 10. In a five-dial decade register, the units dial will rotate 10,000 times for a 1/10 incremental rotation of the ten-thousands dial. The thousands, hundreds, and tens dials will be proportionally rotated along with the movement of the lowest and highest order dials.
In photoconductive encoding registers of prior construction there has been a problem of obtaining a 9.degree. switching (on to off) of a photocell. This 9.degree. switching must be maintained to get an accurate reading. One difficulty has been enabling enough light to reach the cell to activate it. More particularly, a hole through which the light passes had to be so large that a light blocking code wheel made much more than a 9.degree. turn before blocking out the light and turning the photocell off.